Certain proteins and peptides that occur in nature exhibit the ability to self-assemble into materials that have unique properties including elasticity, tensile-strength, toughness, and resilience. For example, spider silk is one of the strongest known fibers in nature. Other examples include β-amyloids like those responsible for Alzheimer's disease as well as optically active self-assembling reflectins, and on the mesoscale like the bundled α-helical coiled-coil elastic protein of the Giant Clam, Tridacna maxima. While nature has created many elaborate proteins capable of complex self-assembly and ligand binding, fabricating materials with the same level of structural and molecular specificity on various length scales remains a challenge.
Polymers are currently being used to generate fibers for tissue engineering scaffolds. Nonwoven nanofibril particulates composed of non-degradable and degradable polymers for tissue engineering applications have been generated. Such matrices are used to promote rapid cell growth, and can also be generated from the present inventive electronically active protein nanowires to include specific amino acid sequence growth factors. Although there has been interest in using protein fibers as biomaterials, effective production of engineered materials that have the desired dimensions and properties faces considerable technical challenges.